External‐Field‐Free Spin Hall Switching of Perpendicular Magnetic Nanopillar with a Dipole‐Coupled Composite Structure
External‐Field‐Free Spin Hall Switching of Perpendicular Magnetic Nanopillar with a Dipole‐Coupled Composite Structure
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DOI：
10.1002/aelm.201901368
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发表时间：
2016-02
影响因子：
6.2
通讯作者：
Zhengyang Zhao;A. Smith;M. Jamali;Jianping Wang
中科院分区：
文献类型：
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作者：
Zhengyang Zhao;A. Smith;M. Jamali;Jianping Wang
自旋霍尔效应（SHE）引起的垂直磁化反转由于其在低功耗存储器和逻辑器件中的潜力而引起了人们的极大兴趣。然而，开关需要辅助的面内磁场，这阻碍了其实际应用。在这里，介绍了一种新的方法，用于垂直纳米磁体的无外场自旋霍尔开关。该方法利用由面内偏置层产生的局部偶极场来辅助切换。在没有任何外磁场的情况下，285 × 95 nm 2垂直CoFeB纳米磁体的鲁棒开关被证明。通过微磁模拟来说明开关过程的磁动力学。在复合纳米器件中获得了135 Oe的大面内补偿场，反映了强对称性破缺行为。与其他提出的无外场自旋霍尔开关方法相比，偶极耦合复合结构与各种自旋霍尔系统和垂直磁性隧道结兼容，为实际的基于自旋轨道扭矩的存储器和逻辑应用铺平了道路。
Spin Hall effect (SHE)‐induced reversal of perpendicular magnetization has attracted significant interest, due to its potential for low‐power memory and logic devices. However, the switching requires an assisted in‐plane magnetic field, which hampers its practical applications. Here, a new approach for external‐field‐free spin Hall switching of a perpendicular nanomagnet is introduced. This approach utilizes a local dipolar field arising from an in‐plane biasing layer to assist the switching. Robust switching of a 285 × 95 nm2 perpendicular CoFeB nanomagnet is demonstrated in the absence of any external magnetic field. Micromagnetic simulation is performed to illustrate the magnetic dynamics of the switching process. Large in‐plane compensation field of 135 Oe is obtained in the composite nanodevices, reflecting a strong symmetry‐breaking behavior. Compared with other proposed methods for external‐field‐free spin Hall switching, the dipole‐coupled composite structure is compatible with a wide range of spin Hall systems and perpendicular magnetic tunnel junctions, paving a way towards practical spin–orbit torque‐based memory and logic applications.